This is just for fun. Substitute any numbers in here for your own calculations.
There are estimates that visible universe contains over 5X10^22 stars so for the sake of argument let us say that there could be 10^24 stars even if we overestimate the number.
“Sun-like” stars of the correct size and composition are probably 1/100 of the total stars (10^22).
Approximately 1/1000 of the total number of stars are in the galactic habitable zone (10^19).
Approximately 1/10 of the sun-like stars will have a rocky planet in orbit (10^18).
Approximately 1/10 of the sun-like stars will have a gaseous planet in an outer orbit that helps protect the rocky planet from catastrophic impacts (10^17).
Approximately 1/100 of the rocky planets will have a large moon that helps protect the rocky planet from catastrophic impacts (10^15).
Approximately 1/100 of the rocky planets will have an orbit that allows surface temperatures necessary for the establishment of long term evolution (10^13).
Approximately 1/100 of the rocky planets will have a sufficient amount of water that will allow the formation of large oceans necessary to buffer temperature fluctuations and help form the correct atmospheric conditions necessary for life and long term evolution (10^11).
Approximately 1/10 of the rocky planets will have a correct atmospheric composition necessary for life and long term evolution (10^10).
Approximately 1/10 of the potentially inhabitable planets will evolve single cell life(10^9).
Approximately 1/10 of the planets with life will evolve different life forms that will generate a CO2-O2 carbon cycle (10^8).
Approximately 1/10 of the planets with life will evolve life forms that will have “mitochondria” for energy utilization (10^7).
Approximately 1/10 of the planets with life will evolve multi-cellular life (10^6).
Approximately 1/10 of the planets with multi-cellular life will evolve complex organisms (105).
Approximately 1/10 of the planets with complex organisms will evolve life on land (10^4).
Approximately 1/10 of the planets with life on land will evolve advanced animal life (10^3).
Approximately 1/1000 of the planets with advanced animal life will evolve civilizations (10^0).
With this type of calculation there are X number of plantets with civilizations.
There are estimates that visible universe contains over 5X10^22 stars so for the sake of argument let us say that there could be 10^24 stars even if we overestimate the number.
“Sun-like” stars of the correct size and composition are probably 1/100 of the total stars (10^22).
Approximately 1/1000 of the total number of stars are in the galactic habitable zone (10^19).
Approximately 1/10 of the sun-like stars will have a rocky planet in orbit (10^18).
Approximately 1/10 of the sun-like stars will have a gaseous planet in an outer orbit that helps protect the rocky planet from catastrophic impacts (10^17).
Approximately 1/100 of the rocky planets will have a large moon that helps protect the rocky planet from catastrophic impacts (10^15).
Approximately 1/100 of the rocky planets will have an orbit that allows surface temperatures necessary for the establishment of long term evolution (10^13).
Approximately 1/100 of the rocky planets will have a sufficient amount of water that will allow the formation of large oceans necessary to buffer temperature fluctuations and help form the correct atmospheric conditions necessary for life and long term evolution (10^11).
Approximately 1/10 of the rocky planets will have a correct atmospheric composition necessary for life and long term evolution (10^10).
Approximately 1/10 of the potentially inhabitable planets will evolve single cell life(10^9).
Approximately 1/10 of the planets with life will evolve different life forms that will generate a CO2-O2 carbon cycle (10^8).
Approximately 1/10 of the planets with life will evolve life forms that will have “mitochondria” for energy utilization (10^7).
Approximately 1/10 of the planets with life will evolve multi-cellular life (10^6).
Approximately 1/10 of the planets with multi-cellular life will evolve complex organisms (105).
Approximately 1/10 of the planets with complex organisms will evolve life on land (10^4).
Approximately 1/10 of the planets with life on land will evolve advanced animal life (10^3).
Approximately 1/1000 of the planets with advanced animal life will evolve civilizations (10^0).
With this type of calculation there are X number of plantets with civilizations.